Detergent briquette



Patented July 6, 1 948 DETERGENT BRIQUETTE James Douglas MacMahon, Niagara Falls, N. "Y.,

assignor to Mathieson Chemical a corporation of Virginia Corporation,

No Drawing. Application July 21, 1945,

Serial N0. 606,484 v H This invention relates to improved briquetted detergent compositions and more particularly to detergent briquettes characterized by a unique combination of detergent characteristics and other physical and chemical properties which mak them highly satisfactory for use in mechanical washing operations.

Modern mechanical methods and apparatus for washing dishes, milk cans and the like, particularly where operation is continued or prolonged, have presented the serious problem of maintaining an alkali concentration in the wash tanksbetween desirable and restricted limits. Commercial experience has shown that this may be accomplished in a dependable and virtually automatic manner by dissolving alkaline briquettes in suitable auxiliary equipment and dispensing the resulting solutioninto the wash tanks at a predetermined rate. A very considerable amount of research has been carried on in view of developing detergents having chemical and physical characteristics satisfactor 'for this purpose.

The problem presented involves, not merely the production of a material or mixtures of material having the desired detergent characteristics but also the development of a product which, in addition to meeting that requirement, can be economi'cally' produced in the desired physical form possessing other essential physical characteristics. For instance, it is desirable that the detergent be in'briquette form; that the briquette be sufliciently hard and strong to withstand ordinary handling; that the briquette be chemically and physicall' stable and non-deliquescent so as to withstand storage and the necessary handling and of such structure as will not disintegrate under the conditions of use.

' Inasmuch as the control of the rate at which the alkali is dispensed into the washing operations largely depends upon the dissolving rate of the briquette, it is desirable that the briquette not only have a satisfactory degree of uniformity in its composition but also that it have a uniform solubility rate. It is, of course, also essential that the composition of the cleansing material be such as to'avoid harmfully afiecting the material being washed either by attacking the material or forming deposits or coatings thereon. It is further essential that the composition of the detergent be such as to avoid deleteriously affecting the parts of the mechanical washer and the deposition of scale in the various chambers thereof.

It has been proposed to produce detergent briquettes for such use by fusing the detergent or detergent mixturesand casting the fused material by drawing it oii into molds to cool. For example, briquettes have been produced by fusing mixtures of trisodium phosphate and soda ash. However, the relatively high temperature required to fuse the detergent or detergent mix- '7 Claims. (Cl. 252-) tures has been a decided handicap in the production of satisfactory detergent briquettes, as many substances, the presence of which is highly desirable in detergent mixtures, are driven'oflf or decomposed at temperatures below thefusion point or at temperatures necessary for fusing other desirable constituents. r

This temperature requirement has not per mitted the incorporation in detergent mixtures so produced of many effective water conditioners and surface active agents, such as synthetic detergents and wetting agents. Consequently, the use of such fused detergent briquettes has'not been wholly satisfactory. For instance, particularly under adverse'water conditions, their use has resulted in the precipitation of the natural hardness of the water supply and the -tendency to form scaleon the inner surface of the mechanical washers with-which the detergent is used. Rapidity of this scale formation depends upon the degree and nature of hardness ofthe water and, in general, increases with the concentration of the hardness of the water supply. If not periodically removed, this scale interferes with the normal functioning of the equipment. Further, this precipitated hardness interferes to a greater or lesser extent with the cleansing operation,

The presence of water conditioners, such as the water conditioning,polyphosphates, for instance "tetrasodi'um pyrophosphate "(Nad -20v). sodium tetraphosphate (N316P4O13), sodium tripolyphosphate (NasPsOm) and sodium hexametaphosphate (NasPeOm) in the alkaline solution tanks of the mechanical washers has been found to inhibit or greatly retardscale formation. Also, the addition of surface active agents, such as the non-saponaceous, organic, synthetic detergents, has been found further to enhance the cleansing action and to effect improved rinsing. However, for the'reasons stated'above, the incorporation of these materials in such anhydrous detergent briquettes formed by fusion at high temperatures has been impractical.

Detergents have heretofore been'produced in block form by crystallization or solidification of the detergent or detergent mix-tures from aqueous solutions; for instance, by the evaporation of water therefrom or by causing a chemical or physical union of the water or a'portion thereof wi-ththe detergent. The resulting blocks of detergent material'have usually been reduced to a granular or powdered form'before use. It has also been proposed to use such detergent blocks in detergent operations. However, so far as I am aware, the detergent blocks produced according to the prior literature of the, art have fallen short of the requirements essential to their satisfactory commercial use in mechanical washing operations. a

which permit incorporation therein of water conditioners and surface active agents, such as pre viously mentioned, by the use of various ingre-r l dients including silicates in -proportionswithin rather definite ranges. Howeyer, in certain specialized purposes, the use of adetergentcom taining a silicate may be objectionable. 4

As distinguished from detergent briquettesof' that general type containing a silicate ;a s an essential ingredient, the briquette of my present invention need contain, no silicate whatever, though unobjectionable. small proportions of ica e a --i d whe e e i I 'I hag/" e v npw discovered that briquettes having the reai ire rh siealz r i and s ial able for use. in mechanical washing operations, may be prepared, free frqm silicates, from detergent nrigctures comprising bprax, water.and either trisodium phosphate or soda ashorb'oth, in proportions Within the limitsv herein defined Without restart-to high fusion teniperatures and that, when SQQ compounded, various surface active agents, such the.. synthetic, detergents. and water conditioning,polyphosphates, such as pre vio noted, inay 'be incorporated in thebriquettewithout destroyingits desirable physical Dra er e s a Thedetergentmixtures, oiwhich thebriquettes or present invention are. composed, consist essentially oteither trisodium phosphate ,0! soda ash, a borate, and water, Adyantageously, it also; contain a water conditioning polyphosphate, such as previously noted, though Ithepresence of such polyphospha'teisinotessential to the productionfoi "a briquette having the desired ,physical properties While, it is not essential; that both w en man te nd ium r onat be used, the presence of both is frequently advan tageous indetergent. operations, and where. desired, v both lmay'beiincluded in -the briquettes of my present invention 'without detrimentally. affe ctin'g' their physical. properties. Other, deterglentga'ids', forl instance suriace active agents, mayel i ael sd 3 Where a detergentof higher alkalinity is dee i e ca siia e am e d dt the et en mixture in amounts approximating, those re: quired. .to give an alkalinity equivalent, to. that 5 of then etab orate. Where lower alkalinityis re,- quired, a relativelys nallproportion of, sodium bicarbpnate,,Ina Qy bev added tothe mixture. At ii hei'falkalinity, the presence of some, t'ris'o {phosphate is desirable in orde'r to attain optimum molding conditions.

. Caustic soda and boraig maythus be. useddn proportions equivalentto sodium metaborate, f or instance, as well as other borates,oi intermediate cnmposition obtained by. the action ,otcaustic on oidinar'yborax;

he P rt f. h -s ve a e redi nts may be varied over a considerable range, as herein specified, to ineetspecific detergentrequirements, However, in orderto'obtain briquettes having the ire i h sical n n'e r i s i ece sa v tha mer ing jjo f variation of pifoporti ons of thesevl d nt e W hin at r wentefinedglin its Bli he sep rat st i, m que t s he iod um phfi rhaie onsti u n ma e, hi er duced in the form of the ordinary commercial hydrated product, generally representedbythe' proportions of water contained therein.

..proximately 53%.

tions specifiedmereinare based upon the latter fi mechanical washing operations, and for other,

armu a. Na BQi-LQ Theoretic lly h ir a =Q ieins ai s: fl r s e analysis indicates that the water content of the trisodium phosphate which I have used in the development of my improved briquette is ap- Consequently, the propor- Trisn 'um phosphate having a higher or lqwe waterboritent may be used providing appropr iate compensation be used for the different Also,

"riiate'rials which react under the compounding conditions to form trisodium phosphate, for in stance disodium phosphate and caustic soda, may be. substituted for an, equivalentp fopor tion of the trisodium phosphate, appropriate al lowance being made for the watercontentotsuch reacting materials and water prOducedby'the reactions.

As previously noted, trisodium phosphate need not be used in my present briqnettes. on the other handit may beusedinproportions ranging' up to as high as about one-half the formula weight.

Thesodiumcarbonate constituent of my bri quette, when used, may, conveniently. be, sup; plied as anhydrous sodaasnandthe proportion and ranges of proportionsspeoified herein are based onv the use of sodium carbonate in that form, However, it, maybe supplied in the form of a hydrate, such as ajrnono ordecahydrate, appropriate allowance being madeifor the, difier ences in compositions. Similarly, the sodium carbonate may besuDplied in the forrn ofinaterials, su'ch as sodium bicarbonate and, caustic soda, which reactunder the compounding con ditionsto forrmsodium carbonate.

The'proportionof the, sodium carbonate constituentiof my improved briquette is subject'to considerable latitudeot .variation to meetpar ticular, detergent requirements. As previously noted, the sodiumcarbonate constituentmay be entirelyomitted, ifdesired. On the otherl and, sodium carbonatemay b e incorporated in my. briquette .in proportions. ranging, as high as about one-halter the formulaweight.

Whereeither trisodium phosphate orsoda ash is omitted, the other should be,;used in anampunt not less than about one-tenth the. fonmularweight,

Similarly, wherebotl are, used, the amount should aggregate not less than about one-tenth of the formulaweight. The a gregate an ountjof these two materials may. range ashigh as about onehalf'theformula weight.

Similarly, polyphosphates are notessential con: stituentsj of the briquettes 01 my present invention but one or more of the Watereconditioning polyphosphate s, such as previously noted may s a y. n or oratedw van a e. ere ql s ha ss re, to f re q ngra ed, my br'iquettesf'l have found that "PIQPQI'tiQns of he r -Y e ht sjflsua r uflie em or mesh. nd tion n pur o e n t qrrl tions oi any one or more of X said polyphosphates aggregating about 15% of-the formula weight may be incorporatedin these briquettes without destroying" their desirable briquetting-properties; However, where eithertetrasodium pyrophosphate or sodium tri-polyphosphate is used-aloneor-in conjunction with; the otherpolyphosphatesnoted; a total amount-of the polyphosphates-inexcess of 15% may with "advantage be incorporated in the briquettes, say up to about50%, without seriously aiIectingdetrimentaHy the moldingtimebr the physical structureof -*theresulting briquetteportions of trisodium phosphate in the upper stituent.

provided not more than about of these other polyphosphates is used. This 15% proportion may be increased to about provided there is a'preponderanoe of tetrasodium pyrophosphate present.

The amount of water present in the detergent composition is of major importance with respect to molding time and mechanical structure of the resulting briquette. It is also of importance with respect to the active detergent content of the briquette. I have found the permissible range of proportions of water in my briquetted product to be from about to 50%. Within this range of proportions, the water may :be varied without encountering any destructive effect on the physical structure of the briquette. However, I have found that proportions of water approaching the lower limit of this range, say about 30% to result in more desirable pouring, congealing and structural characteristics of the resulting briquette. The less desirable conditions generally encountered as the proportion of water approaches the upper limit of this range may, to a considerable extent, 'be corrected by using proportion of the prescribed range for that con- In determining the quantity of water, if any,

to be added as such in the compounding of my vaporized or lost during compounding of de-' .tergent mixtures. However, if compounded bv the process herein described, the amount of water thus lost is usually of no particular consequence. If the amount of water thus lost is excessive, additional water may be added to the batch.

The proportion of the borax constituent of my briquette calculated as anhydrous borax may be varied from as low as about 1% to as high as about 30%. i As the proportion of the borax constituent approaches the lower limit of this range, I have-generally observed an increase in the required molding time which is particularly noticeable where no trisodium phosphate is present. This tendency may to a considerable extent be corrected by the use of higher proportions of the trisodium phosphate constituent. Where no trisodium phosphate is used, it is generally preferable to use an amount of iborax in the upper half of the prescribed range in order to obtain the optimum molding characteristics.

Also, where the proportion of borax is in the lower part of the range, improved molding characteristics are obtained by the addition of one or more of the sodium poly-phosphates herein noted. Also, where no trisodium phosphate is used, the desirable proportion of borax for molding characteristics may be decreased by the inclusion of a sodium polyphosphate, particularly tetrasodium pyrophosph'ate or sodium tripolyphosphate.

An important aspect of my present invention is my ability to control, to a very substantial extent, the solubility rate of my briquettes. This aspect of the invention is particularly advantageous where the briquetted productisto be used in mechanical washers, forexample, with hot water. Where such use is anticipated, the solubility rate of the briquette may be decreased by increasing the proportions of the borate constituent and, conversely, where an increased stable ingredients.

solubility rate is desirable, this maybe effected by reducing the proportion of the borate conamount of either of these materials alone.

The borate constituent is preferably added in the form commercially known as borax and which has the formula NazBaOmlOI-IzO.

The compounding of my improved detergent briquette is advantageously effected in accordance with the process described in my co-pending application Serial No. 582,575, filed MarchlB,

As therein described, the compounding operation is advantageously carried out in a conventional steam-jacketed kettle equipped with a stirring device. Excellent results in preparing and duplicating the composition and structure of the briquettes have been obtained by adhering to the following general procedure: The trisodium phosphate, borax, caustic soda, or sodium bicarbonate, or such of these as are to be used, and additional water, if any, in predetermined amounts, are first added to the kettle. The mixture is heated and. agitated until the mass is fluid and has assumed its maximum clarity, at which time the soda ash or the polyphosphate, or both, are added, if such is to be used. The mixture is then drawn off or poured into molds. During the mixing and pouring the mixture is maintained at a temperature below that at which substantial evolution of steam would occur with the resultant material loss in water. Higher temperatures are to be avoided as it is desirable to reduce to a minimum the amount of water lost during the compounding operation and to avoid decomposition of less By minimizing the water lost during the compounding operation, the proportion of water in the product may be effectively controlled by regulation of the total amount of water added'to the batch. The maximum temperature to which the material is heated depends primarily upon the concentration of the solution in the fluid mass but it is usually found to be within the range of about 70 C. to about C.

When a surface active agent, such as the previously-noted synthetic detergents, is to be incorporated in the briquettes, it is usually desire.-

able to add such material just prior to pouring.

They maybe added in proportions ranging. as

high as about 5% of anhydrous active ingredient.

I have observed that where the amount of borax or of the surface active agent approaches the upper limit of the prescribed range, there is a tendency toward a relatively more fluid mass in the kettle,.and that under such conditions the proportion of water may be reduced slightly beseveral-hours depending uponthe composition amass? Iof :the mixture. On cooling, :det'ergent *compositions of this type seem to. expand somewhat; and this, combined with their tendency to adhere to metal-surfaces, has :previouslyipresented'difiiculty in the moldin'g of detergent -mater-ials. "By; using flexible brique'tte =molds, such as rmolds, made of rubber 'or similar material, as described in the above referred-to co-pending application, these *difiiculties are eliminated.

My invention will be further describedand specifically illustrated by thezfollowing examples of. :proportions and 'ranges of proportions of the several constituents which have been used with advantage :in the preparation .of my improved br-iquettes. it will be understood, however, that the invention is not limited 'tofiproducts prepared from the particular formula shown. In-cachinstance, the percentages given are the percentages -'by.weight and are on the anhydrous .'basis.. For

convenient reference to the composition o'futhe resulting briquette, the respective formulae have beensconsecutively numbered. I

Trisodiurn Soda Example No. Phos hate Borax Total- '20.. o 13. o 32. o as 25.10 34. 1. 0 40 60,0 5.0 as 2.5 36.5 21.0 40 28..'2 11.2.. :6,; to 23.2 31.2 10.6 18.8 23.5 2.1 28.2 16.2 10.6' 35 28.. 2 16. 2. l0. 6 35 0.0 45.0 10.0 35

' ln addition to the constituents shown in tlie' fo'regoing tabulation, Example 7 contained 20% of tetrasodiunl pyrophosphnte, Example 8 contained 10% sodiumretraphosphate, Example '9 contained 10% of sodium hexmmemphosphate, and Example 10 contained: 10% of tetrasodium pyrophosphate.

. Example 1- of the above tabulation. illustrates theaapproximate. upper limit of the permissible rang-s ot the borate constituent and Example :2 .is-il-lustrative of a briquette containing the minimum proportion of bora-te. Example 3-isi1-lustrative of the maximum, proportion of trisodium phosphate and the. complete exclusion ofsoda ash, whileExample. 10 is illustrative of a briquette containing no tr-isodium Phosphate and anE amount of soda ash approaching: the-upper permissible limit. Examples 5 and 6 are illustratiye; o-fthe maximum. and minimum, amounts, respectively, of Water, the other constituents,- with the exception. of soda ash, remaining constant.

each of the foregoing examples, the briouetted product was physically stable, hard,.

strong and non-deliquescent, and satisfactory =foruse in mechanical washing operations.

Though I have described my improved briquettes as particularly adapted for, usewith'me- :chanicahwashers, it will ,be understood that they.

jstrong,andlnonedeliquescent, consistingiofiardense; l6

crystalline aggregate consistingessentiallyof the 'followingconstituents in proportions by :weight within the respective indicated ranges: total water about 30,'-5ll%, atleast one-detergent oithe-group consisting of sodium carbonate and trisodium. phosphate aggregating from about one-tenth to about one-half the total formula, weight, and about 130% of borax.

. s 3. A- detergent briquette physically stable, hard, strong and non-deliquescent, consisting of a dense crystallineagg'regate consisting essentially of the followingsconstituents in proportionsby weight withinthe respective indicated ranges: total water about, 30%-50%, at least one detergent of the group consistingof sodium carbonate and trisodium phosphate aggregating from about onetenth to about one-half the total formula weight, about 1-30-% of. borax, and up to about 15% of a sodium polyphosphate.

-4. Adetergent briquette physically stable-hard, strong and non-'deliquescent, consisting of a dense crystalline aggregate consisting essentially of the following constituents, in proportions by weight within the respective-indicated ranges: total water about 305Q%, at least one detergent of the group consisting of sodium carbonate and trisodium phosphate aggregating from about one-tenth to about one-half the total formula Weight,- about 1-,-3(l:% of borax, and up :toabout 50% 0f tetra- -sodium pyrophosphate. l

15. A'detergen't briquette physically stable, hard, strong and nondeliquescent, consisting of a. dense crystalline aggregate consisting essentially'of the following constituents in proportions by weight within the-respective indicated ranges: total, water about:30=50%, at least one detergent-of the group consisting of sodium carbonate and trisodium phosphate, aggregating from about one-tenth to about one-half the total formula weight, about 1-30% of borax, and up to about 50% of sodium tripolyphosphate. 1 l

6; A detergent briquette physically stable, hard,

strong and non-'deliquescent, consisting of a dense crystalline aggregate consisting essentially of the following constituents in proportions by weight within the respective indicated ranges: total water .about3Q-50% sodium carbonate from about oneabout 1-30% of'borax.

7%. A detergent briquette physically stable, hard, strong andmon-deliquescent,consisting"of a dense crystalline aggregate consisting essentially of the following constituents in proportions by weight within the respective indicated. ranges: totalwater about; 30;-5 0%, sodium carbonate from. about onetenth toabout one-half the total formula weight,

sodium, tripolyphosphate up to about 50%, and about 1 -30% of, borax JAMES DOUGLAS-MACMAHDN;

nnnnnnnons onrnn I l I Tire-following references are of record in the 'file 'of this patent:

UNITEDv STATES- PATENTS Number I Name Date 1,759,152 Booth et al. May 20; 1930 12,035g652 --Hall Mar; 31', 1936 21645092 Smith J'llne2'7; 1939 IEQREIGN PATENTS Number I Country .Date

. Great. Britain Sept 26, 1935 

